Type bar actuating mechanism for typewriters



1952 A. TOMBOLINI TYPE BAR ACTUATING MECHANISM FOR TYPEWRITERS Filed Jan. 6, 1949 Patented Jan. 15, 1952 OFFICE TYPE-BAR ACTUATIN G' MECHANISM' FOR TYPEWRITERS Alfredoslombolini; Milamltaly ApplicationJanuar-y 6, 1949, Serial No. 69,486 In Italy January 31, 1948" 9 Claims; 1

' This invention is for improvements in' the type har actuating mechanism for typewriters;

I-nmodern typewriters one important'object to achieveis particularly thatof providing a soft oreasy keyboard; This requires provision of a type bar actuating mechanism with which depressing of thekey bars is soft or easy, inorder toreduce as much as possible the fatigue of the typist and at the sametime" to increase the-writing speed of the typewriter.

It has heretofore been customary to cause the type bars to be-actuated by a mechanism of a type; similar to that shown in U. S. Patent No. 2,248,691, i. e., by meansof a conjunction lever which is engaged in a slit of the rear end of the type bar to be actuated. The arrangement of such conjunction-levers gives rise to a'great inconvenience as said levers describe such a movement that the fixing journal of the conjunction lever (sliding inthe slit of thetype-bam gets too near to the point of fulcrum of the type bar itself'and, owing to the gradually greater resistance which ensues, the keys gradually become stiffer,

and cause loss of time in operating, imperfect impression of the letters, unsatisfactory multiple copies, etc.

Manystudies-havebeen made since 1890up to the present to eliminate" the above-mentioned diiiiculties, and as a result, most of theknown typewriters now make useof apulling element, of metallic wire, attached to the type bar end in-such a manner that the pulling element can follow-the path of the type bar, thereby pulling and moving it, so that its other end which carries the type, 'ispressed against thetpaper arranged on therubber roller of the typewriter. This'partial advantage of the known type barv actuating devices is, however; accompanied: by another great inconvenience, namely, the fact that the type bars are not singly, easily and rapidly, removable from their supporting segment. To remove any type bar in such known devices, it is necessary first to extract from one side of the segmentlthe semicircular axis on which all the 42 or 45 type bars are supported. This is a great inconvenience both .No.-. 2,198,520;- but the arrangement of; said ;plates 2 requires consideration of the fact that incutting the slits of the segment the width-of saidslits must be increased to make the space for the. conjunction plates.

The improvement accordingto' thepresent in:- vention consists in the fact that applicant has discovered an arrangement whereby a conjunction plate-can be made to cooperate with the-rear end of the type bar, not'by arranging thisplate to the side of its respective. type bar end, but by inserting and hookingthe plate to. said type bar n the same plane as thebar end, the bar end and the plate operating within thesegmentslit, so that'allsegment slits need be. only the width of the thickness of thetype bar end.

The improvement accordingzto this-invention is achieved by the particular shapeof said plate, and of the corresponding rear endof each type bar.

The invention will' be easily understoodfrom the following description made with reference to the annexed-drawing, in which:

Figure 1 shows a modern type baractuating mechanism for typewriterswith soft actuation of the keys, to which the improvement according to this invention is applied.

Figure 1a is a view partly in section and partly in perspective showing the plate of. thisinvention in its relation to the segment and thesemicircular axis.

Figure 2 shows the end ofthe type barand the conjunction plate according to thisinvention;

Figure 3 shows the same inserted and hooked together;

Figure 4' shows the spring holding the plate in inserted and hooked position on the type bar.-

With reference to the annexed drawing: I indicates the plate according to this invention and 2 indicates the type bar; 3 is the pulling element with one end attached to the plate I andlwithits other end mounted ona straight bridge (not shown) arranged beneath the semicircular: segment 9. 5 and '5 are other'actuating elements of th mechanism and 'i' is the key: bar. 4' is a spring, of the type shown in Figure 41 used in maintaining the type. bar: in inserted? and hooked position with its plate;

The plate! has a bore ia throughwhich passes the semicircular axis lb: which: is common tora'll plates and which is inserted. in acorresponding bore of the semicircular'segment; the plate I? has acutout I at the left of the bore ta andla: hook I" attheright'of said bore asshown in 'Figure12.

Correspondingly; .tl'ierrear" endiof theltypie bar' 2 has: a; complementary shapev allowing said: type bar end tcsbednsertedandi tdibezho'okedx on. said bar end has a hook 2' at the left, and a cutout 2 at the right, of a central cutout area, which cutout area receives that central part of the plate I which contains the bore la as shown in Figure 2.

The manner in which the type bar end s inserted in and hooked on the plate is clearly visible from Figure 3.

The spring 4 is a safety means. One end of spring 4 is fastened to the plate. The other end of spring 4 is U-shaped and is hooked over the type bar end which end is notched or is provided with a recess to retain the U-shaped end of spring 4.

As may be seen and understood from Figure 1, which shows the two terminal positions of the type bar (the rest position being shown in full lines and the writing position being shown in plate; the type broken lines) during the actuating movement from rest to writing position, plate I activates the type bar 2 with its hook portion I", while the cutout I retaining the type bar end hook 2' aids in preventing the type bar from becoming unhooked from the plate under the impact of the type bar both at the end of the actuating moveknown in all typewriters, but by the spring 4.

To remove a single type bar 2, it is merely necessary to pull on it from the type end so as to extract it from the segment, exerting sufiicient pull to overcome the tension of spring 4 (after having, of course, removed all interference to this operation caused by the said universal bar). To re-insert the single type bar it is suflicient to push it into alignment with the plate, overcoming again the resistance of the U-shaped end of the spring 4, under which the hook 2 must enter.

The mechanism according to this invention, due to the improvement described, combines two advantages which up to now have not been achieved in the known type bar actuating mechanisms, namely:

(a) Soft actuating of the keys; and

(b) The possibility of removing any single type bar without the necessity of removing the semicircular axis.

What I claim is:

1. An improved type bar actuating mechanism for typewriters comprising a semicircular segment with slits and a semicircular bore, a semicircular axis inserted in said bore, type bars each inserted with the base end thereof in a slit of the segment, conjunction plates having a complementary shape with the base ends of said type bars, each of such conjunction plates being inserted in a slit of the segment so as to lie in the same plane as and to engage the base end of a type bar so as to function as one piece with said type bar, each type bar being supported by its respective conjunction plate, each of said plates being apertured at a central portion thereof to receive said semicircular axis, and a key-actuated pulling element attached to each of said plates.

2. An improved type bar actuating mechanism for typewriters comprising a semicircular segment with slits and a semicircular bore therein, a semicircular axis inserted in said bore, type bars each inserted with its base end in a slit of the segment, conjunction plates having a complementary shape with the base ends of the type bars, each of said conjunction plates inserted in .a slit of the segment so as to lie in the same ,plane as and to engage the base end of a type bar so as to function as one piece with said type bar, each type bar being supported by its respective conjunction plate, each of said plates being apertured at the central portion thereof to receive said semicircular axis, the base end of each type bar having a hook-shaped portion fitting over said central portion of said plate, and a keyactuated pulling element attached to each of said plates.

3. An improved type bar actuating mechanism for typewriters comprising a semicircular segment with slits and a semicircular bore therein, a semicircular axis inserted in said bore, type bars each inserted with the base end thereof in a slit of the segment, conjunction plates having a complementary shape with the base ends of said type bars, each of such conjunction plates being inserted in a slit of the segment so as to lie in the same plane as and to engage the base end of a type bar so as to function as one piece with said type bar, each type bar being supported by its respective conjunction plate, each of said plates being apertured at a central portion thereof to receive said semicircular axis and having a hook portion and a cutout portion, each type bar base end having a complementary hook portion and a cutout portion interfitting with the hook portion and the cutout portion of said plate, and a keyactuated pulling element attached to each of said plates.

4. An improved type bar actuating mechanism for typewriters comprising a semicircular segment with slits and a semicircular bore therein, a semicircular axis inserted in said bore, type bars each inserted with the base end thereof in a slit of the segment, conjunction plates having a shape complementary with the base ends of said type bars, each of such conjunction plates being inserted in a slit of the segment so as to lie in the same plane as and to engage the base end of a type bar so as to function as one piece with said type bar, each type bar being supported by its respective conjunction plate, each of said plates being apertured at a central portion thereof to receive said semicircular axis, each of said plates having a hook portion at one side of said central portion and having a cutout portion at the other side of said central portion, each type bar base and having a hook portion and a cutout portion, said hook portion of said type bar base end being of complementary shape with said cutout portion of said plate and hooking over the central portion of said plate in interfitting engagement with said cutout portion of said plate, said hook portion of said plate being of complementary shape and hooking in interfitting engagement with said outout portion of said type bar base end, and a keyactuated pulling element attached to each of said plates.

5. An improved type bar actuating mechanism for typewriters as claimed in claim 4 including a spring, one end of which is fixed in said conjunction plate and the other end hooked over the hook portion of said type bar base end for demountably holding said conjunction plate and said type bar in assembled relation.

6. An improved type bar actuating mechanism as claimed in claim 5 in which that end of the spring hooked over the hook portion of the type bar base end is U-shaped and the hook portion of said type bar base end is notched for engagement with the U-shaped end of said spring.

7. In a typewriter having a semicircular segment with slits, a semicircular bore therein and a semicircular axis inserted in said bore, a conjunction plate inserted in a slit of said segment and pivotally attached to said axis, a type bar, the base end of said type bar being inserted in said slit in supported engagement with said plate, said plate and said type bar base end lying in the same plane and formed with interfitted, interlocked complementary portions, and a key-actuated pulling element attached to said plate.

8. A type bar having at one end a hook portion and a cutout portion and a complementarilyshaped conjunction plate having a cutout portion and a hooked portion fitting said hook portion and said cutout portion, respectively, of said type bar so as to function as one piece with said type bar, said conjunction plate provided with means I for pivotally mounting said conjunction plate and said type bar.

9. A type bar as set out in claim 8 includin resilient meansfor demountably holding said conjunction plate and said type bar in assembled relation.

ALFREDO TOMBOLINI.

REFERENCES CITED The following references are of record in the m file of this patent:

UNITED STATES PATENTS Number Name Date 966,170 Curtis Aug. 2, 1910 2,198,520 Tombolini Apr. 23, 1940 

